The invention relates to the field of the furniture industry. It relates to a work table with a height- and tilt-adjustable work table.
The height for working on conventional office tables is generally designed such that a keyboard can be beneficially operated ergonomically in an upright sitting position.
With the help of familiar table height adjustments it is therefore possible to adjust the height for users of various heights. The height adjustment generally ranges from 68 to 76 cm.
The continuously upright position however is generally associated with problems for the human locomotor system because the intervertebral disks are exposed to increased pressure.
Orthopedics and industrial scientists are therefore calling for as frequent a position change as possible. This prevents on the one hand the static tightening of muscles and premature fatigue, on the other hand it is easier on the intervertebral disks because it causes alternating tightening and relaxing processes for the muscles and the spine.
Work tables have therefore been developed, with which an adjustment of the work surface to the different user situations can be realized so that a user can work selectively while standing up or while sitting.
For example we know from DE 197 46 911 A1 of a desk with a height-adjustable desk frame and a work top that is fastened to the table frame. This work top is additionally equipped with a desk top that is movable in relation to the work top, and a swivel arrangement is provided in order to allow adjustment of the desk top in relation to the work top with regard to its inclination and height through swiveling about an axis of rotation, wherein the pivot axis is positioned outside the table top so that the table top is raised and lowered at the same time as the swivel movement. The swivel arrangement comprises a rigid connecting element that is arranged on the desk frame so as to be able to swivel about the axis of rotation, with this element carrying the desk top, and a hand lever, which engages in the connecting element in the area of the axis of rotation. The disadvantage of this technical solution is the fact that the user is not able to change between a sitting and a standing activity quickly and as required by the respective situation. It is only when this change can occur with one operation that this change can take place as frequently as is ergonomically desired. Additionally, the desk adjustment mechanism is not designed so as to allow a lying working position. For a potential user, however, the change between a sitting working position and phases of lying and standing working positions is particularly important because in the standing working position the spine automatically takes on its natural S-shape, while in the lying position a complete relaxation of the intervertebral disks occurs.
The invention represents an attempt to avoid the above-mentioned disadvantages of the familiar state of the art. It is based on the task of developing a work table with a tilt- and height-adjustable work surface, which enables the user easily and quickly to change between upright sitting, almost lying and standing working positions. The operation of a keyboard, e.g. on a notebook computer, should be possible in all three positions without difficulty.
Based on the invention this is accomplished on a work table, consisting of a frame with a vertical central column as well as a base and a height- and tilt-adjustable work surface, which is fastened to a support element, through the fact that at the upper end of the central column a joint seating device is provided, about whose horizontal axis a swivel arm is seated in a pivoting manner, wherein the swivel arm contains another rotary joint, about whose horizontal axis the support element and thus the work surface are seated in a pivoting manner.
The benefits of the invention consist of the fact that it is possible to adjust the work surface easily and quickly to the working height during lying, sitting and standing positions.
It is useful if a leg rest, which is fastened to the central column through a support fork, is incorporated on the central column. This allows the user to rest his legs comfortably in the lying working position.
Furthermore it is useful if the support fork is axially displaceable on the central column and rotatable about the vertical axis because this ensures a height and depth adjustment of the leg rest.
Additionally it is beneficial if the support fork can be rotated about the horizontal axis. This allows an individual adjustment of the inclination of the leg rest.
And finally it is advantageous if the swivel arm and the support element are seated in a continuously pivoting manner about the horizontal axes. This way, individual height adjustments for the above three working position is provided.
It is also beneficial if between the swivel arm and the support element a cable pull is arranged because this enables a synchronous rotating coupling between the two parts. The support element is then always aligned horizontally when the swivel arm is aligned vertically, while the support element is tilted by about 25xc2x0 when the swivel arm is aligned horizontally.
It is useful when in the swivel arm a blockable gas pressure spring is arranged, which on the one hand is arranged in a bearing at an angle beneath the joint seating device and on the other hand in a bearing roughly in the center in the swivel arm. This arrangement between the central column and the swivel arm causes the gas pressure spring to experience a lift during the swivel motion between the vertical and the horizontal positions of the swivel arm. This lifting movement can be blocked with the gas pressure spring at any random location, which ensures a swivel fixation of the components and thus a fixation of the work surface.
Furthermore it is beneficial if the gas pressure spring in the unblocked state has a gas spring thrust pressure, which compensates for the inherent weight of the work surface, the support element and the swivel arm because the user can then swivel the swivel arm away with little effort.
And finally it is useful if the base contains swivel rollers. The work table can thus be transported without effort.